Membrane switches are well known for providing electrical switching functions in a reliable, compact package. Membrane switches typically have a flexible plastic membrane layer normally separated from a substrate by a nonconductive spacer. Openings in the spacer permit a user to push the membrane through the spacer, bringing facing electrical contacts on the internal surfaces of the membrane and substrate into contact with one another, thereby closing a switch. The natural resilience of the membrane returns the membrane to its spaced position upon removal of the actuating force.
While this basic membrane switch construction has many advantages, it does not provide some features desirable in certain applications. For example, in some instances switch users are so accustomed to manipulating a particular type of mechanical actuator that they become confused by a membrane switch. The membrane switch is often a flat panel with graphical elements indicating where to press but having no protruding actuating member. Although membrane switches provide perfectly adequate electrical switching, manufacturers have found that users expecting to find a rotary switch or a slide switch or a push button switch for a certain function are resistant to having the familiar mechanical actuator replaced with a flat panel membrane switch. This is especially true with consumer products. Also, in automotive applications it can be important to provide a rotary or slide switch that a driver can find and manipulate with one hand while not diverting his or her attention from the road. Another difficulty with membrane switches is they are not readily adapted for use as a potentiometer such as might be desirable for, say, a volume control on a radio or CD player.
Rotary and slide switches suitable for use with flat panel switches such as membrane switches are known. Examples are shown in U.S. Pat. Nos. 5,523,730, 5,666,096, and 5,867,082. One of the problems in the past has been the inability to conveniently apply such switches directly to film-based switch panels. The present invention addresses this issue.